In recent years as semiconductor devices are manufactured to an ever higher degree of integration, there are increasing demands for setting a higher accuracy for lithography process conditions. Moreover, along with higher integration, demands are also becoming more severe for accurately finding a process window showing the dose range and focus range of the exposure device for manufacturing patterns at a high accuracy. Patent document 1 discloses a pattern evaluation method that synthesizes the contours of two or more identical patterns and utilizes this synthesized contour as a reference pattern. Patent document 1 describes performing a pass/fail inspection by utilizing this reference pattern as an object for comparison.